Drying apparatus



Nov. 24, 1925- G. D. HARRIS DRYING yAPPARATUS Filed Oct. 25, 1920 2 Sheets-Sheet 2 3. 2. :T T f\-|- rlnlvlmf rk ....L-

ATTORNEY j Patented Nov. 24, 1925.

UNITED STATES PATENT OFFICE.

GORDON DON HARRIS, OF ISLIP, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS TO THE INDUSTRIAL DRYER CORPORATION. OF STAMFORD, CONNECTICUT, A CORu PORATION OF CONNECTICUT.

DRY ING APPARATUS.

Application filed October 23, 1920. Serial No. 419,052.

To all whom t may concern:

Be it known that I, GORDON DON HARRrs, a citizen of the United States, residing at Islip,-county of Sulolk, and State of New York, have invented a certain new and useful Drying Apparatus, of which the following is a specification.

This invention is a drier wherein material is transported within a chamber in which heated air, or other drying atmosphere, is circulated for exchanging heat for moisture.

According to one form of apparatus, the material carrier is arranged for transporting looped lnaterial in a form known in the art as testoons, such material being a continuous sheet of paper, textile` or other substance, although it is to be distinctly understood that the invention vnot restricted to the art of drying festoons of web material.

The operation of drying material while the latter is suspended from a carrier must, or should, be conducted under such conditions as involve a minimum disturbance of the festoons of material, and to this end provision is made in this apparatus for the circulation of the drying atmosphere downwardly within the chamber through which the material is carried.

Furthermore, it is desirable in this art to subjectrthe material to a drying atmosphere possessing a certain moisture content, and for economy in the consumption of the energy necessary to heat the drying atmosphere, it is desirable, also, to utilize a certain volume of the heated moist atmosphere which is circulated within the drying chamber, Accordingly, provisionyis made for recirculating a certain volume of the heated moist atmosphere by withdrawing it from the drying chamber, and concurrently with such withdrawal, some' of the heated moist air is discharged from the apparatus, and at the same time a certain volume of fresh atmospheric air is mixed with the heated moist atmosphere, the resulting mixed air being again heated to a desired vtemperature as the atmosphere flows toward the chamber within which the material is carried. l

To these ends, the apparatus in a practical embodiment of the invention includes a drying chamber in theA upper part of which is ari-:1 nged a carrier of one form or another, said carrier being provided with means, such as hangers. from which the material is suspended. Said drying chamber 1s open at one or both ends for the free entrance and exit of the carrier and the festooned material, one of said open ends of the chamber constituting an entrance vestibule and the other open end constituting an exit vestibule, which vestibules are closed, at least partially, by the suspended material. The floor of the drying chamber is provided with a desired number of exits for the drying atmosphere, said exits being in communication with a subjacent flue to which is connected the intake of a circulating device, such as a blower, whereby warm moist air in a desired volume is exhausted by the blower from the bottom portion of the drying chamber through said exits provided in said floor.

Cooperating with said drying chamber are a plurality of exit flues and a plurality of heating chambers, it being preferred to position the exit flues at one side of the drying chamber whereas the heating chambers are on the `opposite side of said chamber", the carrier operating to transport the suspended material in a path intermediate the exit flues and the heating chambers.

The exit lues are vertically positioned .within said drying chamber, each flue being open at the lower end for the tree ingress of warm moist air from said chamber, whereas the upper end of said flue is open to the atmosphere, the arrangement of the lues interiorly of the chamber exposing the walls of said lues to the heating elect of the hot drying atmosphere circulating in the chamber, whereby the open ended tlues provide means for the automatic exit from said chamber ot' the drying atmosphere in a limited volume.

The heating chambers heretofore mentioned are open at their upper ends and are in communication with the drying chamber at the upper portion thereof, in order that the drying atmosphere may flow from the heating chambers into the drying chamber and thence pass downwardly into said drying chamber and upon the suspended material, the direction ot' such downward llow ing toward the looped ends of the suspended material, whereby the circulation of the communication with a duct to which is con- -nected the blower, and provision is thus made for the blower to recirculate the drying atmosphere by exhausting it in a desired volume through the floor of the drying chamber and blowing it into the top of said chamber, the reeirculated air being mixed with fresh atmospheric air drawn by the blower through the open vestibules of said drying chamber, and such mixture of warm moist air with fresh atmospheric air flowing through the heating chambers in order that the mixed air may be heated to a desired temperature prior to the circulation of such atmosphere downwardly within the drying chamber.

Other features and advantages of the invention will appear from the following description 4taken in connection with the drawings, wherein Figure 1 is a side elevation of a drying apparatus embodying this invention, said view illustrating in vertical section the heating chambers on one side of the drying chamber and showing by dotted lines the vertical eduction flues -for the escape of a limited volume of the drying atmosphere.

Figure 2 is a horizontal sectional plan view in the plane of the dotted line 2-2 of Figure 1, the suspended material being omitted.

Figure 8 is a vertical transverse section in the plane of the dotted line 3-3 of Figure 1, showing the course of re-circulat-ing the drying atmosphere and the exit iues for limited volume of the drying atmosphere from the drying chamber.

Figure 4 is a side elevation illustrating an apparatus of increasedcapacity through which the suspended material is adapted to be carried continuously.

A designates a drying chamber of any desired dimensions and capacity., the respective ends a, b, being open s'o as to constitute an entrance vestibule a and an .exit vestibule Extending lengthwisel within this chamber, close to and parallelwith the top thereof, is a trackway on the rails 0 of which are adapted to travel the rollers c of a movable carrier C, the latter 'being shown as coinposed of roller chains provided at suitable intervals with hangers, one of which is shown at C in Fig. 3 as a stick over which the web of material, shown at M in Figs. 2 and 3, is looped for the purpose of the `automatic discharge of ainducing the upward suspending estoons of the web from the carrier.

The floor B of'chamber A is provided with exits (l for drying atmosphere, any desired number and arrangement of said exits being employed for the flow out of the chamber of that Volume of the drying atmosphere which isto be mixed with fresh atmospheric air and to be reeirculated within said chamber A. As shown, the floor i's provided with two series of exits, one series being adjacent each side wall of the chamber. Beneath the floor is a iue D with which the exits d have free communication, and to this bottom Hue is connected the intake e of an air circulating device herein shown as a blower E, the latter being positioned exteriorly of the chamber and preferably adjacent the entrance vestibule a, see Fic'. 2.

n the side wall a', of chamber A is provided a plurality of heating chambers F, whereas the other side wall a2 of said chamber is constructed, with a pluar'ality of iiues lThe heating partitions f one chambers are separated by from the other, so that the chambers afford distinct enclosures for the heating appliances, the latter being of any suitable or approved character, such as coils F for steam, water, gases, etc. Said chambers are positioned exteriorly with reference to the drying chamber, and the end chambers of the series terminate adjacent to,. but at a suitable distance from, the. open ends of the drying chamber, thus establishing the entrance vestibule a and exit vestibule. b, see Figs. 1 and 2.

The inner boundary wall a2 of the chambers F terminates, for a part of its length, at a suitable distance below the top of chamber A, see Fig. 3, and thus the upper ends of heating chambers F are leftfopen-so as to establish spaces of large area, which spaces serve the function of ports f2 for the free flow of the drying atmosphere from chambers F into the top portion of drying chamber A, see the arrows in Figs. 1 and 3. The lower end portions of chambers F are open at fs for free communication with a duct F" to which is connected the outlet e of blower E, the bottom f* of said duct being inclined as shown in Fig. 1 and producing a tapermg duct F2 by which the drying atmosphere is supplied uniformly to therseveral heating chambers.

A desired number of fines G are provided on the side wall 0, of chamber A, said iiues being positioned interiorly of said chamber (see Figs. 2 and 3). for the purpose of subjecting the walls of said iues to the heating eifect of the drying atmosphere flowing within chamber A, whereby the walls constituting lues Gr are heated with a view to flow within the iues of a certain volume of the moist atmosphere from chamber A. Each flue is open at the lower end to produce an inlet g, see Fig. 3, whereas the upper end ofthe flue terminates in a flange forming an outlet g open to the outside atmosphere. The inlets g `to the series oi' lues are above the floor B of drying chamber A in order that the down-{iowing air within said chamber may be free to enter the fines, the hot walls of which tend to induce an upward flow of some of the moist drying air from chamber A, and thus the iues are temperature controlledu-'itli' a view to serving as means for the automatic discharge of a certain volume oi the moist air from said drying chamber. c

In operation, the heating agent is supplied to the coils F, the web of material is supplied to the carrier (l, the carrier is set'in motion, and blower E is drivenby a belt acting on the pulley c2 of the fan shaft. The festoons'or loops of the web hang freely from the sticks C of the carrier, said loops being carried by the conveyor within chainber A and the lower ends of said loops sweeping close to the floor B. The `suspended looped material substantially closes the entrance vestibule and exit Vvestibule b against the escape of an ap reciable volume of the drying atmosphere rom said chamber, the direction of flow of the drying atmosphere under the exhausting action of the blower being from the top downwardly within the chamber and toward the exits l in the floor thereof; but while the blower' acts to circulate the drying atmosphere downwardly within the chamber, the suction of said blower through exits'd operates also' to draw in fresh atmospheric air through the open vestibules a Z) at the respective ends of the chamber, which inflow of fresh air takes place in the spaces leftlA around the lower looped ends of the suspended material and the walls and Hoor ot' the chamber, said indrawn fresh atmospheric air being mixed with the heated moist air within the chamber and the resulting mixture owing through the exits d into flue D and thence to the blower. Said blower forces the air into'dnct F2 by which it is conducted to chambers .l F, thence through ports f2 and downwardly within chamber A, air iiowing upwardly within chambers F and heated i by coils F to a desired temperature. l

The drying atmosphere under the impul-- sion ot' the blower circulates downwardly within the chamber, through exits il, Aflue D blower E, ductfFz, chambers Wand-ports f2 back to chamber A, so tht is is reecircu- `lated in order to utilize to a certain extent ,the heat of said atmosphere and to attain economy in the consumption of steam, as

well .as to utilize'tfhe humidity of the moist,

air in the treatment of 'the material; but during the cycle of the rte-circulation, some vthe suction of the blower through the vestibules a, b, as a result of which the air to be recirculated is conditioned both as to tempcrature and humidity 'or the efficacious and economical treatment of the material.

In my invention the air is blown downwardly upon the festoons or loops of the web material suspended Within the drying chamber, and moist air is mechanically eX- hausted from said chamber below the bottoms or closed bights of said festoons or loops. The effect of blowing air downwardly upon the suspended loops or festoons is to supply a drying atmosphere between the walls of the loops or festoons in such manner as to disturb the suspended material to the least possible extent, whereby swaying of the suspended material is precluded while such material is moved or carried within the chamber. By exhausting air from the bottom portion of the chamber, moist air is removed from the presence of the material, facilitating the-drying operation., The air while in the process of recirculation by the fan is boosted or reheated toa desired temperature, andas such reheated air iiows into contact with the moist material, I am thus enabled to exchange heat for moisture in carrying out the operation of drying the web. It will be noted that the operations of blowing air downwardly upon the web, and of exhausting'air vfrom below the web, secures a positive circulation of air within the festoons or loops of the suspended material, and for` the Jfull depth of such festoons.

My invention involves ra mode of dryine' and conditioning material in web form, suc i as paper, while the same is suspended in loops or festoons, and is undergoing transportation, within a substantially closed chamber, whereby said web of paper is not only idried, but its physical condition is improved owing to the fact that the drying atmosphere, usually air, is blown downwardly upon the loops or festoons and across the web, and moist air is exhausted from below said web, and the air recirculated into kcontact with the web is conditioned as regards its moisture'content and temperature. The treatment which includes blowing air-downwardly upon the web andA within the festoons, and exhausting air from the closedbottoms of the -festoons or loops, has the effect not only of securing a desired circulation and the removal of moist .air from the presence of the web, but the downward How of air within the festoons tends to spread the webmateria-l so as to pxreclude'oifsetting of the Acoatedsurfaces when coated material is undergoingtreatment, and, furthermore, such treatment precludes the sus-` lao pended loops from swaying 'within the drying chamber. Again,` the paper is dried without concentrating the downwardly flowing air upon the middle` portion of the web, with a consequent' y .tendency to establish spots or streaks in the web or in the coated surface thereof, and concurrently with the 'drying of the paper it is conditioned by the air which carries a. certain moisture content, the temperature and the. moisture content of such air serving to mddify the condition of the air itself. This conditioning of the drying atmosphere is due to the fact that it is composed in pait of moist heated air exhausted from the drying chamberand in part'of fresh atmospheric air mixed with thel moist air, and to the further fact that such mixed air. is reheated or boosted during the recirculation of them'air by the blower, such boosting or reheating of the mixedr air being effected at a period subsequent to exhausting the air from the drying chamber and prior' to there-turn of the air back to side lsaid drying chamber. heaters F are positioned exteriorly to the The boosters or redrying chamber and at intervals along the length of said drying chamber, adjacent one wall thereof. Said reheaters or boosters are positioned within separate compartments or chambers, the function of which is to divide or channel the'flow of' air, and the upper ends of which compartments deliver the mixed and conditioned atmosphere downwardly upon the suspended web, the'lower'ends of said compartments or chambers being supplied with air, modified or conditioned as to its moisture content, by the action of the blower, the latter exhausting the moist air fromtthe bottom portion of the drying chamber and delivering such air to thc succession ofair channeling chambers, from which chambers the drying atmosphere, conditioned as to its moisture content and f temperature, is distributed along the length of the web suspended within thedrying chamber.

It is to be understood that the material is transported at the desired speed 'within chamber A by the movement (either continuously or intermittently) of carrier C, and simultaneously therewith the drying atmosphere, conditioned as described, is circulated and re-circulated in a manner to ,v flow downwardly `within the` chamber, be-

tween the walls of the depending loops and toward the lower,y closed ends of such 1003s, the effect of which is to exchange heat or l moisture with a minimum disturbance of fincreasedl by the multi-unit construction depicted in Fig. 4 wherein two or more of the chambers A and blowers E may be,

employed; the units being positioned in end to end relation with a. vestibule '7L intermediate said chambers, suitable provisionv` ly upon the web so as to flow within the.

festoons thereof, and means for exhausting the drying atmosphere from said chamber below the suspended festoons therein.

2. Drying apparatus embodying a chamber having an entrance-'vestibule and an -exit vestibule, means forv carrying a web suspended in festoons within said chamber, means for feeding a drying atmosphere downwardly upon said web so as toiow within the festoons thereof, means for exhausting the drying atmosphere from said chamber and below the suspended festoons 'thereim and temperature-.controlled eductionrflues the entrance to which is at the lower part ofthe chamber and the exit frfim which is open to the outside atmosphere for establishing a vent for some of the moist air independent of the exhausting means.

3. In a drier, a chamber the respective ends of which are open and constitute an entrance vestibule' and an exit vestibule, means for conveying material within said chamber and the vestibules thereof whereby 'said materialpartially closes the vestibules while making provision for the infiow therethroughof atmospheric air, and means for circulating a drying atmosphere downwardly within said chamber, said circulating means having an intake connection with said chamber for inducing the inflow of atmosphericair through said vestibules.

4. In a drier, a drying chamber the floor of which is provided with""ports `for the outflow of a drying atmosphere, means for conveying material within said chamber and in the direction of the length thereof, a heater containing chamber the outlet of which is positioned for discharging a drying medium into the top of said drying chamber, and a circulating device the intake of which is supplied from the ports in the floor and the outlet of which is connected with said heater containing chamber. 'i

5. Drying apparatus embodying a chamber having an entrance vestibule and an exit vestibule, means for carrying a web suspended in festoons within said chamber7 means for recirculating a drying atmosphere in such manner as to exhaust the same from the chamber substantially below the susl the suspended' festoons, and flues exit ot some ol the moist air from saidv pended festoons and to return the same to said chamber by blowing downwardly upon for the chamber independently of said recirculating means.

6. In a drier, the combination of a drying chamber the Hoor of which is provided with outlets for a drying atmosphere and the inlet for which atmosphere is adjacent the top of said chamber, a material carrier, a series of temperature-controlled eduction lues the intakes of which are adjacent the floor of said chamber and the outlets of which liues are open to the external atmosphere, andr means 'lor exhausting the drying atmosphere through said outlets in the oor and for feeding said atmosphere through said inlet.

7 In a drier, the combination of a drying chamber provided with an entrance vestibule and with an exit vestibule, a material carrier, a plurality of heater-containing chambers positioned Jfor feeding a drying atmosphere to the chamber at points intermediate said vestibules, and a circulating device the intake of which yis supplied with a drying atmosphere from the lower part of said chamber and the outlet from which circulating device is connected-with said heater-containing chambers.

8. In a drier, a drying chamber provided with an entrance vestibule and anv eXit vestibule, a material carrier, a circulating device the intake of which is connected for eX- hausting a dryin medium from the lower portion of said rying chamber, a heatercontaining chamber to which is connected 4the outlet from said circulating device, said heater-containing chamber operating to deliver a drying medium to the drying chamber above the plane of the material carrier, and a temperature controlled eduction flue through which a limitedv volume of the moist drying medium is free to escape from said drying chamber.

9. In a drier, a drying chamber, a material carrier, means Jfor re-circulating a drying atmosphere within said chamber and downwardly with reference to the plane of said material carrier, means for heating the drying medium during its `-re-circulation, and temperature controlled eduction lines positioned within the drying chamber and affording means for the automatic youtlet of a limited Volume of the drying medium from said chamber.

lOl In a drier, a drying chamber provided with an entrance vestibule and an exit vestibule, a plurality of heating chambers at one side of the drying chamber, said heating chambers having free communication with the dr ing chamber at the upper portion thereo aplurality of eduction flues positioned within the drying chamber at the opposite side thereof, means for transporting material within said drying chamber and intermediate the heating chambers and the eduction lues, means for circulating a drying atmosphere within the drying chamber and said heating chambers, and heating means within the heating chambers.

11. In a web drier, a material chamber, means for moving therein a web of material suspended in festoons within said chamber, means for channeling the fiow of air and feeding the same into different regions of the chamber and downwardly upon the suspended festoons of material therein, means for exhausting air from the bottom of said chamber and xbelow the suspended festoons therein, and means for heating the separate streams of air flowing within the channeling means. l

12. In a drier, a material chamber, means for moving therein a web of material suspended in festoons within said chamber, means for .recirculating a drying atmosphere the intake of which recirculating means is' below the suspended festoons and the outlet from which directs such atmosphere downwardly upon the suspended estoons, means for dividmg the drying atmosphere so recirculated into a plurality of streams so as to return theatmos here-thus divided and recirculated into different regions of the material chamber, and meansJ for heating the separate streams of the recirculated drying atmosphere.A

`13. In a drier, a material chamber, means for moving therein a web of material suspended in festoons within said chamber, exhaust means from the chamber below the suspended estoons, feeding means at the upper part of the chamber for the delivery of a drying atmosphere downwardly upon the suspended festoons of material, means v for recirculating the drying atmosphere the intake to which. is constituted by the exhaust means and the outlet from which is constituted by the feeding means, means for dividing the liow of the drying atmosphere into a plurality of separate streams intermediate the eX aust means and the feeding means, and means for heating the divide stream of such atmosphere.

14. In a drier, a material chamber, means for moving therein a' web of material suspended in festoons within said chamber, recireulating means the intake of which is at the bottom of said chamber and the outlet of which feeds the drying atmosphere downwardly upon the suspended festoons of material, means for channeling the How of suclf atmosphere so as to divide the same into a' lurality of streams which are returned to dierent re ions of the material chamber, means for ischar 'ng from said material chamber some of t e moist atmospheric air present therein, means for separately heat'- ing the different streams of such recirculated atmosphere, and means for feeding freshs atn'1os1: heric air to the drying atmosphere.

l5. Drying apparatus embodying a chamber, means for moving material 1n a suspended condition within said chamber, circulating means for blowing a drying atmosphere downwardly upon the suspended material, the intake for said circulating means being in comn'iunication with said chamber at the lower portion thereof, means for channeling the flow of said drying atmosphere whereby the return of said atmosphere to the chamber is distributed along the length thereof, and heating means exteriorly to the chamber and in the line of flow of the drying atmosphere during the circulation thereof.

1G. Drying apparatus embodying a chamber having an entrance vestibule and an exit vestibule, means for carrying a web suspended in festoons within said chamber, means for recirculating a drying atmosphere by exhausting the same fronrthe chamber below the festoons and by blowing the same downwardly upon the web so as to flow interniediate the festoons thereof, and heating means positioned exteriorly to the chamber and in the line of flow of the drying atmosphere during the recirculation thereof.

17. Drying apparatus embodying a chamber, means for moving therein a web suspended in festoons, recireulating `means whereby a drying atmosphere is blown downwardly upon the web, said reeirculating means having an intake in communication with the chamber below the Vfestoons suspended therein, and heating means positioned exteriorlyl to said chamber and in the line of flow of the drying atmosphere during the period of its recirculation.

18. Drying apparatus embodying a chamber, means for moving within said chamber la web suspended in festoons, recirculating means whereby a drying atmosphere is blown downwardly upon said web,- the intake for said recirculating means being in communication with said chamber below the festoons of the web to be suspended therein, and a plurality of heaters positioned at intervals intermediate the ends of said chamber, said heaters being exteriorly to said chamber and in the line of low of the drying atmosphere during the recirculation thereof.

19. Drying apparatus including a chamber, means for moving within said chamber a web suspended in festoons, recirculating meansl for blowing downwardly upon said web a drying atmosphere, the intake for said recirculating means being in communication with said chamber below the festoons suspended therein, means for channeling the liow of the drying atmosphere whereby the return of such atmosphere is distributed along the chamber, and a plurality of heaters positioned exteriorly to said chamber and intermediate said channeling means to lie in the line of flow of the drying atmosphere for heating the latter to a desired temperature.

1n testimony whereof I have hereto signed my name this 11th day of October, 1920.

GORDON DON HARRIS. 

